A prior art of this type sample analysis apparatus has been made public in an academic journal of Japan Society of Calorimetry and Thermal Analysis by one of the inventors of this application (see Non-patent Document 1). This applicant has already proposed a gas analysis apparatus disclosed in Patent Document 1 as a gas analysis apparatus which is suitably applicable to the above type sample analysis apparatus.
The apparatus disclosed in the Non-patent Document is designed to have a system configuration in which thermogravimetry and differential thermal analysis for a sample and mass spectrometry of gas evolved from the sample can be simultaneously performed. Particularly, a photoionization method (PI method: photoionization method) disclosed in the Patent Document 1 is adopted for the mass spectrometry of gas. The photoionization method is an ionization method utilizing a phenomenon that upon application of light to a molecule, the molecule releases a photoelectron to be ionized when the photon energy of the light is larger than the ionization energy of the molecule.
A mass spectrometry method based on an electron ionization method (EI method: Electron ionization method) that irradiates gas with an accelerated electron beam to dissociate component molecules contained in the gas and generate fragment ions has been known as an analysis method of gas evolved from a sample. According to this electron ionization method, fragment ions corresponding to all the structural factors of the component molecules contained in the gas are generated, and thus this method is suitable for investigation of the structural factors of the component molecules. However, as the number of the component molecules contained in the gas increases, the fragment ions corresponding to the structural factors of the respective component molecules are overlapped with one another. Therefore, there is a drawback that it is difficult to separate and discriminate those component molecules from one another.
On the other hand, according to the mass spectrometry method utilizing the photoionization method proposed by the inventor in the Non-patent Document 1 and the Patent Document 1, component molecules themselves contained in gas are ionized without being dissociated, the component molecules are separated every molecular weight on the basis of obtained molecular ion information, and the molecular weights of the separated component molecules are determined.
However, in the mass spectrometry method utilizing the photoionization method, fragment ions corresponding to the structural factors of the respective component molecules cannot be obtained, and thus it is impossible to perform the structural analysis of the respective component molecules contained in gas. Accordingly, it is impossible to perform qualitative analysis of identifying component molecules of a sample to which it is unknown what component molecules are contained.
According to an apparatus (GC-MS) for separating gas evolved from a sample into component molecules by using a gas chromatography and per forming mass spectrometry, qualitative analysis of the separated component molecules can be also performed. However, in this apparatus, the gas is temporarily cooled and captured, and then re-heated to perform mass spectrometry. Therefore, it is impossible to simultaneously perform thermal analysis and gas analysis in parallel, and also there is a risk that the gas is degenerated in the cooling and re-heating steps.